Plague - Anne Arundel County Physician's Link
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Plague
CDC, AFIP
Diseases of Bioterrorist Potential
Learning Objectives
Describe the epidemiology, mode of transmission, and
presenting symptoms of disease caused by the CDCdefined Category A agents
Identify the infection control and prophylactic measures
to implement in the event of a suspected or confirmed
Category A case or outbreak
Plague
History & Significance
14th Century: “Black Death” responsible for >20
million deaths in Europe
Used as a BW agent by Japan in WW II
Studied by Soviet and, to a smaller extent, U.S.
BW programs
1995: Larry Wayne Harris arrested for illicit
procurement of culture via mail
Plague
Epidemiology
Caused by Yersinia pestis
About 10-15 cases/year U.S.
Mainly SW states
Human plague occurs from bite of an infected flea
(bubonic)
Only pneumonic form of plague is spread person-toperson
Last case of person-to-person transmission in U.S. occurred in 1924
Yersinia Pestis
Gram negative, nonmotile, non-sporeforming bacillus
Resistant to freezing
temperature and
drying, killed by heat
and sunlight
Source: Centers for Disease Control and
Prevention, Division of Vector-Borne
Infectious Diseases, Fort Collins, CO
Plague
Case Definition
• Characterized by fever, chills, headache, malaise,
prostration, & leukocytosis that manifests in one
or more of the following clinical forms:
–
–
–
–
Regional lymphadenitis (bubonic)
Septicemia w/o evident bubo (septicemic)
Plague pneumonia
Pharyngitis & cervical lymphadenitis (pharyngeal)
MMWR 1997;46(RR-10)
Plague
Case Definition, cont.
Laboratory criteria for diagnosis:
Presumptive
Elevated serum antibody titers to Y. pestis F1 antigen (w/o
documented 4-fold change) in a patient with no history of plague
vaccination OR
Detection of F1 antigen in a clinical specimen by fluorescent assay
Confirmatory
Isolation of Y. pestis from a clinical specimen OR
4-fold or greater change in serum antibody titer to Y. pestis F1 antigen
MMWR 1997;46(RR-10)
Plague: Case Classification
Suspected: Clinically compatible case w/o
presumptive or confirmatory lab results
Probable: Clinically compatible case with
presumptive lab results
Confirmed: Clinically compatible case with
confirmatory lab results
MMWR 1997;46(RR-10)
Plague
Clinical Forms
Bubonic plague
Most common naturally-occurring form
Mortality 60% untreated, <5% treated
Primary or secondary septicemic plague
Pneumonic plague
Most likely BT presentation
From aerosol or septicemic spread to lungs
Survival unlikely if treatment not initiated w/in
24 hours of the onset of symptoms
Pneumonic Plague
Clinical Presentation
Incubation: 1-6 days (usually 2-4 days)
Acute onset of fever with cough, dyspnea, and chest pain
Hemoptysis characteristic; watery or purulent sputum
also possible
Prominent GI symptoms may be present, including
nausea, vomiting, diarrhea, and abdominal pain
Pneumonic Plague
Clinical Presentation
Other symptoms include headache, chills,
malaise, myalgias
Rarely, cervical bubo present
Rapid progression to respiratory failure & shock
Bubonic Plague
Incubation: 2-8 days
Sudden onset nonspecific symptoms: fever, chills,
malaise, muscle aches, headache
Regional lymphadenitis (buboes)
Swollen, very painful lymph nodes
Typically inguinal, femoral, axillary, or cervical
Erythema overlying skin
May have surrounding edema
Concurrent with or shortly after onset of other symptoms
Septicemic & Bubonic Plague
Source: CDC NVBID
Plague
Infection Control
Person-to-person transmission via respiratory
droplets
Standard respiratory droplet precautions
Treatment = 10 days antibiotics
Case isolation for at least the first 48 hrs of antibiotic
treatment
Bubonic plague - standard precautions
Plague
Infection Control
Antibiotic prophylaxis for close contacts
Duration: 7 days or duration of risk of exposure +
7 days
Close contacts refusing prophylaxis:
Observe 7 days after last exposure and treat if
fever or cough develop
Bubonic contacts:
Observe 7d and treat if symptoms develop
Plague
Summary of Key Points
The most likely presentation in a BT attack is
pneumonic plague.
Unlike other forms of plague, pneumonic plague
is transmitted person to person, and thus
respiratory droplet precautions are indicated in
suspected cases until 48 hours after the initiation
of antibiotic therapy.
Case Reports
Plague
Plague Pneumonia - CA. MMWR 1984;33(34)
Pneumonic Plague -- Arizona, 1992. MMWR 41(40)
Resources
Centers for Disease Control & Prevention
http://www.bt.cdc.gov/
Bioterrorism Web page:
CDC Office of Health and Safety Information System
(personal protective equipment)
http://www.cdc.gov/od/ohs/
USAMRIID -- includes link to on-line version
of Medical Management of Biological Casualties
Handbook http://www.usamriid.army.mil/
Resources
Office of the Surgeon General: Medical
Nuclear, Biological and Chemical Information
http://www.nbc-med.org
St. Louis University Center for the Study of
Bioterrorism and Emerging Infections
http://bioterrorism.slu.edu